<?php
/**
 * This file is part of Swoole.
 *
 * @link     https://www.swoole.com
 * @contact  team@swoole.com
 * @license  https://github.com/swoole/library/blob/master/LICENSE
 */

declare(strict_types=1);

$socket = null;
$errno = 0;
$context = stream_context_create(['ssl' => ['local_cert' => dirname(__FILE__) . '/cert.pem']]);

$socket = stream_socket_server('tcp://127.0.0.1:0', $errno, $errstr, STREAM_SERVER_BIND | STREAM_SERVER_LISTEN, $context);
if (!$socket) {
    echo "{$errstr} ({$errno})\n";
    exit("could not start/bind the ftp server\n");
}

$socket_name = stream_socket_get_name($socket, false);
$port = (int) substr($socket_name, strrpos($socket_name, ':') + 1);

$pid = pcntl_fork();

// server
if ($pid == 0) {
    function dump_and_exit($buf)
    {
        var_dump($buf);
        exit;
    }

    function anonymous()
    {
        return $GLOBALS['user'] === 'anonymous';
    }

    /* quick&dirty realpath() like function */
    function change_dir($dir)
    {
        global $cwd;

        if ($dir[0] == '/') {
            $cwd = $dir;
            return;
        }

        $cwd = "{$cwd}/{$dir}";

        do {
            $old = $cwd;
            $cwd = preg_replace('@/?[^/]+/\.\.@', '', $cwd);
        } while ($old != $cwd);

        $cwd = strtr($cwd, ['//' => '/']);
        if (!$cwd) {
            $cwd = '/';
        }
    }

    $s = stream_socket_accept($socket);
    if (!$s) {
        exit("Error accepting a new connection\n");
    }

    fputs($s, "220----- PHP FTP server 0.3 -----\r\n220 Service ready\r\n");
    $buf = fread($s, 2048);

    function user_auth($buf)
    {
        global $user, $s, $ssl, $bug37799;

        if (!empty($ssl)) {
            if ($buf !== "AUTH TLS\r\n") {
                fputs($s, "500 Syntax error, command unrecognized.\r\n");
                dump_and_exit($buf);
            }

            if (empty($bug37799)) {
                fputs($s, "234 auth type accepted\r\n");
            } else {
                fputs($s, "666 dummy\r\n");
                sleep(1);
                fputs($s, "666 bogus msg\r\n");
                exit;
            }

            if (!stream_socket_enable_crypto($s, true, STREAM_CRYPTO_METHOD_SSLv23_SERVER)) {
                exit("SSLv23 handshake failed.\n");
            }

            if (!preg_match('/^PBSZ \d+\r\n$/', $buf = fread($s, 2048))) {
                fputs($s, "501 bogus data\r\n");
                dump_and_exit($buf);
            }

            fputs($s, "200 OK\r\n");
            $buf = fread($s, 2048);

            if ($buf !== "PROT P\r\n") {
                fputs($s, "504 Wrong protection.\r\n");
                dump_and_exit($buf);
            }

            fputs($s, "200 OK\r\n");

            $buf = fread($s, 2048);
        }

        if ($buf == "AUTH TLS\r\n") {
            fputs($s, "500 not supported.\r\n");
            return;
        }
        if (!preg_match('/^USER (\w+)\r\n$/', $buf, $m)) {
            fputs($s, "500 Syntax error, command unrecognized.\r\n");
            dump_and_exit($buf);
        }
        $user = $m[1];
        if ($user !== 'user' && $user !== 'anonymous') {
            fputs($s, "530 Not logged in.\r\n");
            exit;
        }

        if (anonymous()) {
            fputs($s, "230 Anonymous user logged in\r\n");
        } else {
            fputs($s, "331 User name ok, need password\r\n");

            if (!preg_match('/^PASS (\w+)\r\n$/', $buf = fread($s, 100), $m)) {
                fputs($s, "500 Syntax error, command unrecognized.\r\n");
                dump_and_exit($buf);
            }

            $pass = $m[1];
            if ($pass === 'pass') {
                fputs($s, "230 User logged in\r\n");
            } else {
                fputs($s, "530 Not logged in.\r\n");
                exit;
            }
        }
    }

    user_auth($buf);

    $cwd = '/';
    $num_bogus_cmds = 0;

    while ($buf = fread($s, 4098)) {
        if (!empty($bogus)) {
            fputs($s, '502 Command not implemented (' . $num_bogus_cmds++ . ").\r\n");
        } elseif ($buf === "HELP\r\n") {
            fputs($s, "214-There is help available for the following commands:\r\n");
            fputs($s, " USER\r\n");
            fputs($s, " HELP\r\n");
            fputs($s, "214 end of list\r\n");
        } elseif ($buf === "HELP HELP\r\n") {
            fputs($s, "214 Syntax: HELP [<SP> <string>] <CRLF>\r\n");
        } elseif ($buf === "PWD\r\n") {
            fputs($s, "257 \"{$cwd}\" is current directory.\r\n");
        } elseif ($buf === "CDUP\r\n") {
            change_dir('..');
            fputs($s, "250 CDUP command successful.\r\n");
        } elseif ($buf === "SYST\r\n") {
            if (isset($bug27809)) {
                fputs($s, "215   OS/400 is the remote operating system. The TCP/IP version is \"V5R2M0\"\r\n");
            } elseif (isset($bug79100)) {
                // do nothing so test hits timeout
            } elseif (isset($bug80901)) {
                fputs($s, "\r\n" . str_repeat('*', 4096) . "\r\n");
            } else {
                fputs($s, "215 UNIX Type: L8.\r\n");
            }
        } elseif ($buf === "TYPE A\r\n") {
            $ascii = true;
            fputs($s, "200 OK\r\n");
        } elseif ($buf === "AUTH SSL\r\n") {
            $ascii = true;
            fputs($s, "500 not supported\r\n");
        } elseif ($buf === "TYPE I\r\n") {
            $ascii = false;
            fputs($s, "200 OK\r\n");
        } elseif ($buf === "QUIT\r\n") {
            fputs($s, "221 Bye\r\n");
            break;
        } elseif (preg_match("~^PORT (\\d+),(\\d+),(\\d+),(\\d+),(\\d+),(\\d+)\r\n$~", $buf, $m)) {
            $host = "{$m[1]}.{$m[2]}.{$m[3]}.{$m[4]}";
            $port = ((int) $m[5] << 8) + (int) $m[6];
            fputs($s, "200 OK.\r\n");
        } elseif (preg_match("~^STOR ([\\w/.-]+)\r\n$~", $buf, $m)) {
            fputs($s, "150 File status okay; about to open data connection\r\n");

            if (empty($pasv)) {
                if (!$fs = stream_socket_client("tcp://{$host}:{$port}")) {
                    fputs($s, "425 Can't open data connection\r\n");
                    continue;
                }

                $data = stream_get_contents($fs);
                $orig = file_get_contents(dirname(__FILE__) . '/' . $m[1]);

                if (isset($ascii) && !$ascii && $orig === $data) {
                    fputs($s, "226 Closing data Connection.\r\n");
                } elseif ((!empty($ascii) || isset($bug39583)) && $data === strtr($orig, ["\r\n" => "\n", "\r" => "\n", "\n" => "\r\n"])) {
                    fputs($s, "226 Closing data Connection.\r\n");
                } else {
                    var_dump($data);
                    var_dump($orig);
                    fputs($s, "552 Requested file action aborted.\r\n");
                }
                fclose($fs);
            } else {
                $data = file_get_contents('nm2.php');
                $orig = file_get_contents(dirname(__FILE__) . '/' . $m[1]);
                if ($orig === $data) {
                    fputs($s, "226 Closing data Connection.\r\n");
                } else {
                    var_dump($data);
                    var_dump($orig);
                    fputs($s, "552 Requested file action aborted.\r\n");
                }
            }
        } elseif (preg_match("~^APPE ([\\w/.-]+)\r\n$~", $buf, $m)) {
            fputs($s, "150 File status okay; about to open data connection\r\n");

            if (empty($pasv)) {
                if (!$fs = stream_socket_client("tcp://{$host}:{$port}")) {
                    fputs($s, "425 Can't open data connection\r\n");
                    continue;
                }

                $data = stream_get_contents($fs);
                file_put_contents(__DIR__ . '/' . $m[1], $data, FILE_APPEND);
                fputs($s, "226 Closing data Connection.\r\n");
                fclose($fs);
            } else {
                $data = stream_get_contents($fs);
                file_put_contents(__DIR__ . '/' . $m[1], $data, FILE_APPEND);
                fputs($s, "226 Closing data Connection.\r\n");
                fclose($fs);
            }
        } elseif (preg_match("~^CWD ([A-Za-z./]+)\r\n$~", $buf, $m)) {
            if (isset($bug77680)) {
                fputs($s, "550 Directory change to {$m[1]} failed: file does not exist\r\n");
                var_dump($buf);
            } else {
                change_dir($m[1]);
                fputs($s, "250 CWD command successful.\r\n");
            }
        } elseif (preg_match("~^NLST(?: ([A-Za-z./]+))?\r\n$~", $buf, $m)) {
            if (isset($m[1]) && (($m[1] === 'bogusdir') || ($m[1] === '/bogusdir'))) {
                fputs($s, "250 {$m[1]}: No such file or directory\r\n");
                continue;
            }

            // there are some servers that don't open the ftp-data socket if there's nothing to send
            if (isset($bug39458, $m[1]) && $m[1] === 'emptydir') {
                fputs($s, "226 Transfer complete.\r\n");
                continue;
            }

            if (empty($pasv)) {
                fputs($s, "150 File status okay; about to open data connection\r\n");
                if (!$fs = stream_socket_client("tcp://{$host}:{$port}")) {
                    fputs($s, "425 Can't open data connection\r\n");
                    continue;
                }
            } else {
                fputs($s, "125 Data connection already open; transfer starting.\r\n");
                $fs = $pasvs;
            }

            if ((!empty($ssl)) && (!stream_socket_enable_crypto($pasvs, true, STREAM_CRYPTO_METHOD_SSLv23_SERVER))) {
                exit("SSLv23 handshake failed.\n");
            }

            if (empty($m[1]) || $m[1] !== 'emptydir') {
                fputs($fs, "file1\r\nfile1\r\nfile\nb0rk\r\n");
            }

            fputs($s, "226 Closing data Connection.\r\n");
            fclose($fs);
        } elseif (preg_match("~^MKD ([A-Za-z./]+)\r\n$~", $buf, $m)) {
            if (isset($bug7216)) {
                fputs($s, "257 OK.\r\n");
            } else {
                if (isset($bug77680)) {
                    var_dump($buf);
                }
                fputs($s, "257 \"/path/to/ftproot{$cwd}{$m[1]}\" created.\r\n");
            }
        } elseif (preg_match('/^USER /', $buf)) {
            user_auth($buf);
        } elseif (preg_match('/^MDTM ([\w\h]+)/', $buf, $matches)) {
            switch ($matches[1]) {
                case 'A':
                    fputs($s, "213 19980615100045.014\r\n");
                    break;
                case 'B':
                    fputs($s, "213 19980615100045.014\r\n");
                    break;
                case 'C':
                    fputs($s, "213 19980705132316\r\n");
                    break;
                case '19990929043300 File6':
                    fputs($s, "213 19991005213102\r\n");
                    break;
                default:
                    fputs($s, "550 No file named \"{$matches[1]}\"\r\n");
                    break;
            }
        } elseif (preg_match('/^RETR ([\/]*[\w\h]+)/', $buf, $matches)) {
            if (!empty($pasv)) {
            } elseif (!$fs = stream_socket_client("tcp://{$host}:{$port}")) {
                fputs($s, "425 Can't open data connection\r\n");
                continue;
            }

            switch ($matches[1]) {
                case 'pasv':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    // the data connection is handled in another forked process
                    // called from outside this while loop
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case 'a story':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    fputs($fs, "For sale: baby shoes, never worn.\r\n");
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case 'binary data':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    $transfer_type = $ascii ? 'ASCII' : 'BINARY';
                    fputs($fs, $transfer_type . "Foo\0Bar\r\n");
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case 'fget':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    $transfer_type = $ascii ? 'ASCII' : 'BINARY';
                    fputs($fs, $transfer_type . "FooBar\r\n");
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case 'fgetresume':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    $transfer_type = $ascii ? 'ASCII' : 'BINARY';
                    fputs($fs, "Bar\r\n");
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case 'fget_large':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    $transfer_type = $ascii ? 'ASCII' : 'BINARY';
                    if ($GLOBALS['rest_pos'] == '5368709119') {
                        fputs($fs, 'X');
                    } else {
                        fputs($fs, 'Y');
                    }
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case 'mediumfile':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    for ($i = 0; $i < 150; $i++) {
                        fputs($fs, "This is line {$i} of the test data.\n");
                    }
                    fputs($s, "226 Closing data Connection.\r\n");
                    break;
                case '/bug73457':
                    fputs($s, "150 File status okay; about to open data connection.\r\n");
                    break;
                case 'gh10521':
                    // Just a side channel for getting the received file size.
                    fputs($s, "425 Can't open data connection (" . $GLOBALS['rest_pos'] . ").\r\n");
                    break;
                default:
                    fputs($s, "550 {$matches[1]}: No such file or directory \r\n");
                    break;
            }
            if (isset($fs)) {
                fclose($fs);
            }
        } elseif (preg_match('/^PASV/', $buf, $matches)) {
            $pasv = true;
            $host = '127.0.0.1';
            $i = 0;

            if (empty($bug73457)) {
                if (!empty($ssl)) {
                    $soc = stream_socket_server('tcp://127.0.0.1:0', $errno, $errstr, STREAM_SERVER_BIND | STREAM_SERVER_LISTEN, $context);
                } else {
                    $soc = stream_socket_server('tcp://127.0.0.1:0');
                }
                if (!$soc) {
                    echo "{$errstr} ({$errno})\n";
                    exit("could not bind passive port\n");
                }

                $soc_name = stream_socket_get_name($soc, false);
                $pasv_port = (int) substr($soc_name, strrpos($soc_name, ':') + 1);
            } else {
                $pasv_port = 1234;
            }

            $p2 = $pasv_port % ((int) 1 << 8);
            $p1 = ($pasv_port - $p2) / ((int) 1 << 8);
            fputs($s, "227 Entering Passive Mode. (127,0,0,1,{$p1},{$p2})\r\n");

            if (empty($bug73457)) {
                $pasvs = stream_socket_accept($soc, 10);
            }
        } elseif (preg_match('/^EPSV/', $buf, $matches)) {
            fputs($s, "550 Extended passsive mode not supported.\r\n");
        } elseif (preg_match('/^SITE EXEC/', $buf, $matches)) {
            fputs($s, "200 OK\r\n");
        } elseif (preg_match('/^RMD/', $buf, $matches)) {
            fputs($s, "250 OK\r\n");
        } elseif (preg_match('/^SITE CHMOD/', $buf, $matches)) {
            fputs($s, "200 OK\r\n");
        } elseif (preg_match('/^DELE ([\w\h]+)/', $buf, $matches)) {
            if (isset($matches[1]) && in_array($matches[1], ['file1', "file\nb0rk"])) {
                fputs($s, "250 Delete successful\r\n");
            } else {
                fputs($s, "550 No such file or directory\r\n");
            }
        } elseif (preg_match('/^ALLO (\d+)/', $buf, $matches)) {
            fputs($s, '200 ' . $matches[1] . " bytes allocated\r\n");
        } elseif (preg_match('/^LIST www\//', $buf, $matches)) {
            if (empty($pasv)) {
                fputs($s, "150 File status okay; about to open data connection\r\n");
                if (!$fs = stream_socket_client("tcp://{$host}:{$port}")) {
                    fputs($s, "425 Can't open data connection\r\n");
                    continue;
                }
            } else {
                fputs($s, "125 Data connection already open; transfer starting.\r\n");
                $fs = $pasvs;
            }

            if ((!empty($ssl)) && (!stream_socket_enable_crypto($pasvs, true, STREAM_CRYPTO_METHOD_SSLv23_SERVER))) {
                exit("SSLv23 handshake failed.\n");
            }

            fputs($fs, "file1\r\nfile1\r\nfile\nb0rk\r\n");
            fputs($s, "226 Closing data Connection.\r\n");
            fclose($fs);

            fputs($s, "226 Transfer complete\r\n");
        } elseif (preg_match('/^LIST no_exists\//', $buf, $matches)) {
            fputs($s, "425 Error establishing connection\r\n");
        } elseif (preg_match('/^REST (\d+)/', $buf, $matches)) {
            $GLOBALS['rest_pos'] = $matches[1];
            fputs($s, "350 OK\r\n");
        } elseif (preg_match('/^SIZE largefile/', $buf)) {
            fputs($s, "213 5368709120\r\n");
        } elseif (preg_match('/^RNFR existing_file/', $buf, $matches)) {
            fputs($s, "350 File or directory exists, ready for destination name\r\n");
        } elseif (preg_match('/^RNFR nonexisting_file/', $buf, $matches)) {
            fputs($s, "550 No such file or directory\r\n");
        } elseif (preg_match('/^RNTO nonexisting_file/', $buf, $matches)) {
            fputs($s, "250 Rename successful\r\n");
        } elseif (preg_match('/^MLSD no_exists\//', $buf, $matches)) {
            fputs($s, "425 Error establishing connection\r\n");
        } elseif (preg_match("~^MLSD(?: ([A-Za-z./]+))?\r\n$~", $buf, $m)) {
            if (isset($m[1]) && (($m[1] === 'bogusdir') || ($m[1] === '/bogusdir'))) {
                fputs($s, "250 {$m[1]}: No such file or directory\r\n");
                continue;
            }

            // there are some servers that don't open the ftp-data socket if there's nothing to send
            if (isset($bug39458, $m[1]) && $m[1] === 'emptydir') {
                fputs($s, "226 Transfer complete.\r\n");
                continue;
            }

            if (empty($pasv)) {
                fputs($s, "150 File status okay; about to open data connection\r\n");
                if (!$fs = stream_socket_client("tcp://{$host}:{$port}")) {
                    fputs($s, "425 Can't open data connection\r\n");
                    continue;
                }
            } else {
                fputs($s, "125 Data connection already open; transfer starting.\r\n");
                $fs = $pasvs;
            }

            if ((!empty($ssl)) && (!stream_socket_enable_crypto($pasvs, true, STREAM_CRYPTO_METHOD_SSLv23_SERVER))) {
                exit("SSLv23 handshake failed.\n");
            }

            if (empty($m[1]) || $m[1] !== 'emptydir') {
                fputs($fs, "modify=20170127230002;perm=flcdmpe;type=cdir;unique=811U4340002;UNIX.group=33;UNIX.mode=0755;UNIX.owner=33; .\r\n");
                fputs($fs, "modify=20170127230002;perm=flcdmpe;type=pdir;unique=811U4340002;UNIX.group=33;UNIX.mode=0755;UNIX.owner=33; ..\r\n");
                fputs($fs, "modify=20170126121225;perm=adfrw;size=4729;type=file;unique=811U4340CB9;UNIX.group=33;UNIX.mode=0644;UNIX.owner=33; foobar\r\n");
                fputs($fs, "fact=val=ue;empty=; path;name\r\n");
                fputs($fs, "no_space\r\n");
                fputs($fs, "no_semi pathname\r\n");
                fputs($fs, "no_eq; pathname\r\n");
            }

            fputs($s, "226 Closing data Connection.\r\n");
            fclose($fs);
        } elseif (preg_match('/^SIZE \/bug73457/', $buf)) {
            fputs($s, "213 10\r\n");
        } elseif (preg_match('/^SITE/', $buf)) {
            fputs($s, "500 Syntax error, command unrecognized.\r\n");
        } else {
            dump_and_exit($buf);
        }
    }
    exit;
}

fclose($socket);

return function () use ($pid, $port) {
    Co\defer(function () use ($pid, $port) {
        $out = Co\System::waitpid($pid);
        assert($out['code'] == 0);
    });
    return $port;
};
